This Chart Shows How Insanely Expensive Death-Penalty Cases Are

When the American legal system decides to pursue a capital offense, taxpayers can suffer — to the tune of about $1 million.

A new study from Seattle University analyzed 147 aggravated first-degree murder cases since 1997 in Washington state, separating the data into two categories: when prosecutors file a death notice, and when they don't.

On average, a single death-penalty case cost $3.07 million, while a noncapital case cost an average of $2.01 million, leaving a difference of about $1.06 million. Adjusted for inflation in 2015, that means prosecutors seeking the death penalty cost Americans an extra $1.15 million per case, making them 1.4 to 1.5 times more expensive.

The most notable increases occur in defense fees and court costs. While postconviction incarceration costs are higher for non-death-penalty cases, they don't differ that greatly. The punishment for first-degree murder can be any number of years, including life in prison.